What is RNA and DNA in Biology

Like DNA, RNA (ribonucleic acid) is a strand of nucleotides. It is of central importance in protein synthesis (transcription and translation).

A single nucleotide consists of a phosphate acid residue, a ribose (monosaccharide with 5 carbon atoms -> pentose) and an organic base. These can be adenine, cytosine, guanine or uracil. Compared to DNA, the thymine in RNA is replaced by uracil.

As a rule, ribonucleic acid consists of only one strand. This is mainly due to their function. During transcription, for example, the DNA is transcribed (transferred) to the messenger RNA and read again during translation for the synthesis of proteins. The process works so effectively and economically because, compared to DNA, RNA has only one strand on which all information is also contained. Because the complementarity of the bases means that the sequence of the genetic code is also firmly determined on the single-stranded RNA.

Additional knowledge: The so-called RNA world hypothesis includes the idea that our current civilization is a successor to a world based on ribonucleic acid as a general building block for storing information and catalysis of chemical processes. Accordingly, RNA molecules were the first precursors for organisms. This hypothesis can be justified on the basis of the ability of RNA to store, transmit and reproduce genetic information and, as ribozymes (catalytically active RNA), to influence reactions. The deoxyribonucleotide, which is responsible for the assembly of DNA, is originally made from building blocks of RNA. Accordingly, DNA can only be generated if RNA has been built up beforehand in the form of ribonucleotides.